metasenv_length := 0;
context_length := 0
let print_counters () =
- prerr_endline (Printf.sprintf
+ debug_print (Printf.sprintf
"apply_subst: %d
apply_subst_context: %d
apply_subst_metasenv: %d
exception MetaSubstFailure of string
exception Uncertain of string
exception AssertFailure of string
+exception DeliftingARelWouldCaptureAFreeVariable;;
-let debug_print = prerr_endline
+let debug_print = fun _ -> ()
type substitution = (int * (Cic.context * Cic.term)) list
Cic.Meta(n,l) as t ->
(try
deref subst
- (CicSubstitution.lift_meta
+ (CicSubstitution.subst_meta
l (third (CicUtil.lookup_subst n subst)))
with
CicUtil.Subst_not_found _ -> t)
| C.Meta (i, l) ->
(try
let (_, t,_) = lookup_subst i subst in
- um_aux (S.lift_meta l t)
+ um_aux (S.subst_meta l t)
with CicUtil.Subst_not_found _ ->
(* unconstrained variable, i.e. free in subst*)
let l' =
(ppterm subst term)
in
(* DEBUG
- prerr_endline error_msg;
- prerr_endline ("metasenv = \n" ^ (ppmetasenv metasenv subst));
- prerr_endline ("subst = \n" ^ (ppsubst subst));
- prerr_endline ("context = \n" ^ (ppcontext subst context)); *)
+ debug_print error_msg;
+ debug_print ("metasenv = \n" ^ (ppmetasenv metasenv subst));
+ debug_print ("subst = \n" ^ (ppsubst subst));
+ debug_print ("context = \n" ^ (ppcontext subst context)); *)
raise (MetaSubstFailure error_msg)))
subst ([], [])
in
otherwise the occur check does not make sense *)
(*
- prerr_endline ("sto deliftando il termine " ^ (CicPp.ppterm t) ^ " rispetto
+ debug_print ("sto deliftando il termine " ^ (CicPp.ppterm t) ^ " rispetto
al contesto locale " ^ (CicPp.ppterm (Cic.Meta(0,l))));
*)
in
C.Var (uri,exp_named_subst')
| C.Meta (i, l1) as t ->
- (* see the top level invariant *)
- if (i = n) then
- raise (MetaSubstFailure (sprintf
- "Cannot unify the metavariable ?%d with a term that has as subterm %s in which the same metavariable occurs (occur check)"
- i (ppterm subst t)))
- else
- begin
- (* I do not consider the term associated to ?i in subst since *)
- (* in this way I can restrict if something goes wrong. *)
- let rec deliftl j =
- function
- [] -> []
- | None::tl -> None::(deliftl (j+1) tl)
- | (Some t)::tl ->
- let l1' = (deliftl (j+1) tl) in
- try
- Some (deliftaux k t)::l1'
- with
- NotInTheList
- | MetaSubstFailure _ ->
- to_be_restricted :=
- (i,j)::!to_be_restricted ; None::l1'
- in
- let l' = deliftl 1 l1 in
- C.Meta(i,l')
- end
+ (try
+ let (_,t,_) = CicUtil.lookup_subst i subst in
+ deliftaux k (CicSubstitution.subst_meta l1 t)
+ with CicUtil.Subst_not_found _ ->
+ (* see the top level invariant *)
+ if (i = n) then
+ raise (MetaSubstFailure (sprintf
+ "Cannot unify the metavariable ?%d with a term that has as subterm %s in which the same metavariable occurs (occur check)"
+ i (ppterm subst t)))
+ else
+ begin
+ (* I do not consider the term associated to ?i in subst since *)
+ (* in this way I can restrict if something goes wrong. *)
+ let rec deliftl j =
+ function
+ [] -> []
+ | None::tl -> None::(deliftl (j+1) tl)
+ | (Some t)::tl ->
+ let l1' = (deliftl (j+1) tl) in
+ try
+ Some (deliftaux k t)::l1'
+ with
+ NotInTheList
+ | MetaSubstFailure _ ->
+ to_be_restricted :=
+ (i,j)::!to_be_restricted ; None::l1'
+ in
+ let l' = deliftl 1 l1 in
+ C.Meta(i,l')
+ end)
| C.Sort _ as t -> t
| C.Implicit _ as t -> t
| C.Cast (te,ty) -> C.Cast (deliftaux k te, deliftaux k ty)
(* order (in the sense of alpha-conversion). See comment above *)
(* related to the delift function. *)
(* debug_print "First Order UnificationFailure during delift" ;
-prerr_endline(sprintf
+debug_print(sprintf
"Error trying to abstract %s over [%s]: the algorithm only tried to abstract over bound variables"
(ppterm subst t)
(String.concat "; "
res, metasenv, subst
;;
+(* delifts a term t of n levels strating from k, that is changes (Rel m)
+ * to (Rel (m - n)) when m > (k + n). if k <= m < k + n delift fails
+ *)
+let delift_rels_from subst metasenv k n =
+ let rec liftaux subst metasenv k =
+ let module C = Cic in
+ function
+ C.Rel m ->
+ if m < k then
+ C.Rel m, subst, metasenv
+ else if m < k + n then
+ raise DeliftingARelWouldCaptureAFreeVariable
+ else
+ C.Rel (m - n), subst, metasenv
+ | C.Var (uri,exp_named_subst) ->
+ let exp_named_subst',subst,metasenv =
+ List.fold_right
+ (fun (uri,t) (l,subst,metasenv) ->
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ (uri,t')::l,subst,metasenv) exp_named_subst ([],subst,metasenv)
+ in
+ C.Var (uri,exp_named_subst'),subst,metasenv
+ | C.Meta (i,l) ->
+ (try
+ let (_, t,_) = lookup_subst i subst in
+ liftaux subst metasenv k (CicSubstitution.subst_meta l t)
+ with CicUtil.Subst_not_found _ ->
+ let l',to_be_restricted,subst,metasenv =
+ let rec aux con l subst metasenv =
+ match l with
+ [] -> [],[],subst,metasenv
+ | he::tl ->
+ let tl',to_be_restricted,subst,metasenv =
+ aux (con + 1) tl subst metasenv in
+ let he',more_to_be_restricted,subst,metasenv =
+ match he with
+ None -> None,[],subst,metasenv
+ | Some t ->
+ try
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ Some t',[],subst,metasenv
+ with
+ DeliftingARelWouldCaptureAFreeVariable ->
+ None,[i,con],subst,metasenv
+ in
+ he'::tl',more_to_be_restricted@to_be_restricted,subst,metasenv
+ in
+ aux 1 l subst metasenv in
+ let metasenv,subst = restrict subst to_be_restricted metasenv in
+ C.Meta(i,l'),subst,metasenv)
+ | C.Sort _ as t -> t,subst,metasenv
+ | C.Implicit _ as t -> t,subst,metasenv
+ | C.Cast (te,ty) ->
+ let te',subst,metasenv = liftaux subst metasenv k te in
+ let ty',subst,metasenv = liftaux subst metasenv k ty in
+ C.Cast (te',ty'),subst,metasenv
+ | C.Prod (n,s,t) ->
+ let s',subst,metasenv = liftaux subst metasenv k s in
+ let t',subst,metasenv = liftaux subst metasenv (k+1) t in
+ C.Prod (n,s',t'),subst,metasenv
+ | C.Lambda (n,s,t) ->
+ let s',subst,metasenv = liftaux subst metasenv k s in
+ let t',subst,metasenv = liftaux subst metasenv (k+1) t in
+ C.Lambda (n,s',t'),subst,metasenv
+ | C.LetIn (n,s,t) ->
+ let s',subst,metasenv = liftaux subst metasenv k s in
+ let t',subst,metasenv = liftaux subst metasenv (k+1) t in
+ C.LetIn (n,s',t'),subst,metasenv
+ | C.Appl l ->
+ let l',subst,metasenv =
+ List.fold_right
+ (fun t (l,subst,metasenv) ->
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ t'::l,subst,metasenv) l ([],subst,metasenv) in
+ C.Appl l',subst,metasenv
+ | C.Const (uri,exp_named_subst) ->
+ let exp_named_subst',subst,metasenv =
+ List.fold_right
+ (fun (uri,t) (l,subst,metasenv) ->
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ (uri,t')::l,subst,metasenv) exp_named_subst ([],subst,metasenv)
+ in
+ C.Const (uri,exp_named_subst'),subst,metasenv
+ | C.MutInd (uri,tyno,exp_named_subst) ->
+ let exp_named_subst',subst,metasenv =
+ List.fold_right
+ (fun (uri,t) (l,subst,metasenv) ->
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ (uri,t')::l,subst,metasenv) exp_named_subst ([],subst,metasenv)
+ in
+ C.MutInd (uri,tyno,exp_named_subst'),subst,metasenv
+ | C.MutConstruct (uri,tyno,consno,exp_named_subst) ->
+ let exp_named_subst',subst,metasenv =
+ List.fold_right
+ (fun (uri,t) (l,subst,metasenv) ->
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ (uri,t')::l,subst,metasenv) exp_named_subst ([],subst,metasenv)
+ in
+ C.MutConstruct (uri,tyno,consno,exp_named_subst'),subst,metasenv
+ | C.MutCase (sp,i,outty,t,pl) ->
+ let outty',subst,metasenv = liftaux subst metasenv k outty in
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ let pl',subst,metasenv =
+ List.fold_right
+ (fun t (l,subst,metasenv) ->
+ let t',subst,metasenv = liftaux subst metasenv k t in
+ t'::l,subst,metasenv) pl ([],subst,metasenv)
+ in
+ C.MutCase (sp,i,outty',t',pl'),subst,metasenv
+ | C.Fix (i, fl) ->
+ let len = List.length fl in
+ let liftedfl,subst,metasenv =
+ List.fold_right
+ (fun (name, i, ty, bo) (l,subst,metasenv) ->
+ let ty',subst,metasenv = liftaux subst metasenv k ty in
+ let bo',subst,metasenv = liftaux subst metasenv (k+len) bo in
+ (name,i,ty',bo')::l,subst,metasenv
+ ) fl ([],subst,metasenv)
+ in
+ C.Fix (i, liftedfl),subst,metasenv
+ | C.CoFix (i, fl) ->
+ let len = List.length fl in
+ let liftedfl,subst,metasenv =
+ List.fold_right
+ (fun (name, ty, bo) (l,subst,metasenv) ->
+ let ty',subst,metasenv = liftaux subst metasenv k ty in
+ let bo',subst,metasenv = liftaux subst metasenv (k+len) bo in
+ (name,ty',bo')::l,subst,metasenv
+ ) fl ([],subst,metasenv)
+ in
+ C.CoFix (i, liftedfl),subst,metasenv
+ in
+ liftaux subst metasenv k
+
+let delift_rels subst metasenv n t =
+ delift_rels_from subst metasenv 1 n t
+
+
(**** END OF DELIFT ****)